[PATCH v1 2/9] ntfs: fail EA update when reading $EA_INFORMATION fails

[Baolin Liu]

From: Baolin Liu <liubaolin@xxxxxxxxxx>

In ntfs_set_ea(), when the $EA_INFORMATION attribute exists but
reading it fails or returns an unexpected size, the function jumps
to the exit label with err still 0, so setxattr(2) reports success
without writing anything.

Worse, ea_info_qsize is still 0 at that point, so the exit path
calls NInoClearHasEA() on an inode that does have EAs on disk,
hiding all existing EAs until the inode is evicted.

Return -EIO in this case and leave the HasEA flag untouched on
failure.

Fixes: fc053f05ca28 ("ntfs: add reparse and ea operations")
Signed-off-by: Baolin Liu <liubaolin@xxxxxxxxxx>
---
 fs/ntfs/ea.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/fs/ntfs/ea.c b/fs/ntfs/ea.c
index 59e5e86e38e3..10d5b192f07e 100644
--- a/fs/ntfs/ea.c
+++ b/fs/ntfs/ea.c
@@ -208,8 +208,10 @@ static int ntfs_set_ea(struct inode *inode, const char *name, size_t name_len,
 	if (ntfs_attr_exist(ni, AT_EA_INFORMATION, AT_UNNAMED, 0)) {
 		p_ea_info = ntfs_attr_readall(ni, AT_EA_INFORMATION, NULL, 0,
 						&ea_info_size);
-		if (!p_ea_info || ea_info_size != sizeof(struct ea_information))
+		if (!p_ea_info || ea_info_size != sizeof(struct ea_information)) {
+			err = -EIO;
 			goto out;
+		}
 
 		ea_buf = ntfs_attr_readall(ni, AT_EA, NULL, 0, &all_ea_size);
 		if (!ea_buf) {
@@ -390,10 +392,12 @@ static int ntfs_set_ea(struct inode *inode, const char *name, size_t name_len,
 		*packed_ea_size = p_ea_info->ea_length;
 	mark_mft_record_dirty(ni);
 out:
-	if (ea_info_qsize > 0)
-		NInoSetHasEA(ni);
-	else
-		NInoClearHasEA(ni);
+	if (!err) {
+		if (ea_info_qsize > 0)
+			NInoSetHasEA(ni);
+		else
+			NInoClearHasEA(ni);
+	}
 
 	kvfree(ea_buf);
 	kvfree(old_ea_buf);
-- 
2.51.0